At this Kp the oval extends past this location, so aurora can appear anywhere in the sky rather than only near the northern horizon. Kp says how far the oval reaches, not where the arc sits at a given minute — it can be a single band or fade out between substorms — so with clear, dark skies, watch the whole sky, not just north.
Based on NOAA's forecast peak of Kp 2.7 for tonight's dark hours here. A guide, not a guarantee: aurora can beat the forecast or fall short of it, so don't plan a trip on this alone.
One email when the Kp index is forecast to climb, on the nights displays over Arvidsjaur, Sweden get bright and active. Nothing else.
What is Kp? A 0 to 9 scale of how disturbed Earth's magnetic field is. The higher it goes, the further from the poles the aurora can be seen. Most nights sit between 1 and 3, and 5 or more is a geomagnetic storm. More about Kp
NOAA expects a quiet field for the next three days. Aurora is still possible here on any dark, clear night.
Night here Reaches the levelEach bar is three hours of NOAA's Kp forecast, in local time.
Arvidsjaur sits at 65.6° geographic, but the oval is centred on the magnetic pole.
Roughly the activity level at which the oval expands over you. Kp sets the oval's reach, not the arc's exact position at a given moment.
Average across tonight's dark hours. Skies are essentially clear — nothing between you and the aurora. Right now it's 46%.
Dark until 05:19. Aurora is usually best around midnight.
84of the last 365 nights
Kp reached 4 or more during the night hours in Arvidsjaur on 84 of the last 365 nights, the level at which displays here get brighter and more active. The strongest night was November 11, 2025, when Kp reached 8.7.
This counts geomagnetic activity, not sightings. Cloud, moonlight and the light summer nights of high latitudes decide how many of those nights anything could be seen.
The auroral oval is a ring centred on Earth's magnetic pole, not the geographic one. That is why Arvidsjaur — at 65.6° geographic latitude — behaves like a 62.8° location as far as aurora is concerned. A higher Kp pushes that ring further from the pole, which is why your geomagnetic latitude — not your spot on a map — decides the number you need.
From here, aurora starts to clear the northern horizon at around Kp 0, and the oval expands over you at around Kp 2, when displays reach high into the sky. Kp describes the oval's reach, not where the arc will be at a given moment. Find a spot with an unobstructed view north and away from street lighting. Give your eyes twenty minutes to adjust, and remember that a camera picks up colour long before the naked eye does.
One caveat worth knowing: these thresholds are averages, not promises. Kp is a planetary index covering three hours, so it cannot tell you where the aurora is at this minute — for that, NOAA's OVATION model maps the oval half an hour ahead. The real auroral oval moves around with the solar wind and reaches furthest from the pole near midnight, so any given night can run better or worse than the number suggests. Treat it as a good guide to whether tonight is worth your time, not a guarantee.
Kp index and forecast from NOAA SWPC. Cloud cover and sun times from Open-Meteo. Kp history from GFZ Potsdam (CC BY 4.0). Magnetic latitude is AACGM-v2 (corrected geomagnetic), epoch 2026.
